Skydiving daredevil gears up for jump from stratosphere

ROSWELL, N.M.--An Austrian daredevil suited up on Sunday in the hopes of making his long-delayed skydive from a balloon flying 23 miles (37 km) above the planet and breaking the sound barrier.

Crews early Sunday began spreading out the massive but extremely delicate helium balloon so it can be inflated to carry skydiver Felix Baumgartner, 43, into the stratosphere. The launch, scrapped several times during the previous week by high winds, depends on calm skies.

The 30 million-cubic-foot (850,000-cubic-meter) plastic balloon, which is about one-tenth the thickness of a Ziploc bag, roughly as thin as a dry cleaner bag, can only be launched if winds are roughly 2 mph (3 kph) or less between ground level and an altitude of about 800 feet (244 meters).

Baumgartner aims to break a 52-year-old high altitude parachute jump record currently held by project advisor Joe Kittinger. In 1960, Kittinger, now a retired U.S. Air Force colonel, jumped from a balloon flying at 102,800 feet (31,333 meters) and fell for 4 minutes and 36 seconds before opening his parachute. Baumgartner hopes to top that with a jump from 120,000 feet and freefall for 5 minutes and 35 seconds.

There is so little air in the upper reaches of the atmosphere that after about 30 seconds of freefall, Baumgartner should be moving faster than the speed of sound, which is roughly 690 mph (1,110 kph) at that altitude.